I'm not sure if this really is a bug or not as I guess duration would be extracted from the video file itself after you start playing it. If it's working as intended, would it be possible to set the duration to whatever tmdb reports back until the videofile is actually played, thus the correct video time overwrites whatever metadata we have.

When requesting data for a movie, tmdb responds with the runtime (among all other data), but the runtime is not applied to the video items duration which stays blank. This is true for both javascript and ecmascript.